Blog Archive

Monday, 25 February 2008

Weekly BioNews 18 - 25 Feb 2008

Scientists at the University of York have characterised an important new step in the mechanism used by bacteria to evade our immune system.

A multidisciplinary research team from the Departments of Biology and Chemistry at York have been studying how bacteria capture the molecule used to make the ‘cloak’, called sialic acid.

The researchers have now discovered an enzymatic activity that helps in the more efficient capture of sialic acids released from our cell surfaces. As well as using the sialic acid to make the ‘invisibility cloak’ other bacteria use similar methods to capture sialic acid as a simple food source, so are literally eating us from the inside!

Dr Gavin Thomas, of the Department of Biology, who led the research said: "This novel enzyme, as well as other steps required for the formation of the 'invisibility cloak' that we have discovered in York, now offers the chance to develop novel antimicrobials against these bacteria."

Scientists at The Scripps Research Institute have discovered that a mutation in a known DNA recombination mechanism may result in the onset of autoimmunity and an overexpression of autoreactive antibodies—molecules that attack the host—in animal models.

The new study highlights the role of "recombining sequence," a DNA element involved in the genetic reprogramming of immune system B cells, a process called receptor editing. These new findings could point toward a possible novel therapeutic target for autoimmune diseases such as lupus.

"This is the first mutation in which we were able to cripple receptor editing but not affect other processes," said David Nemazee, a Scripps Research scientist and professor of immunology, whose laboratory conducted the study. "This produced mice more prone to autoimmunity."

U.S. scientists have created the largest and most detailed global study of human genetic variation, providing insights into early human migrations.

The researchers from the University of Michigan and the National Institute on Aging said their study offers unprecedented detail, uncovering new clues to humanity's origins, characterizing more than 500,000 DNA markers in the human genome and examining variations across 29 populations on five continents.

"Our study is one of the first in a new wave of extremely high-resolution genome scans of population genetic variation," said Assistant Research Professor Noah Rosenberg, co-senior author of the study. "Now that we have the technology to look at thousands, or even hundreds of thousands, of genetic markers, we can infer human population relationships and ancient migrations at a finer level of resolution than has previously been possible."

A U.S.-British-led international consortium has announced the "1000 Genomes Project" to produce the most detailed map of human genetic variation to date.

The project will involve the sequencing of the genomes of at least 1,000 people from around the world to create the most medically useful human genetics picture ever produced.

Major support for the effort will be provided by the Wellcome Trust Sanger Institute in Britain, China's Beijing Genomics Institute and the National Human Genome Research Institute, part of the U.S. National Institutes of Health.

"The 1000 Genomes Project will examine the human genome at a level of detail no one has done before," said Wellcome's Richard Durbin, consortium co-chairman. "Such a project would have been unthinkable only two years ago. Today Β… it is now within our grasp."

Farmers are upbeat about genetically modified crops, according to new research funded by the Economic and Social Research Council (ESRC).

A group at the Open University, led by Professor Andy Lane, has taken the first systematic look at what large-scale, commodity farmers – not those mainly involved in organic growing - think about genetically-modified crops. We know how consumers, governments and the food industry regard GM, but this is the first proper look at the attitudes of the people who would use GM crops.

Lane and his colleagues found that both farmers who have been involved in GM crop trials and those who have not, regard GM as a simple extension of previous plant breeding techniques, such as those which have produced today’s established crop types. They regard GM crops as an innovation which they would assess on its merits. Their real interest is in how GM crops would work in practice and whether they can contribute to the profitability of their farms. The research suggests that these farmers do not think that GM raises any issues of principle, or that it is a matter of right or wrong.

Bacteria often get bad press, with those found in water often linked to illness and disease. But researchers at The University of Nottingham are using these tiny organisms alongside the very latest membrane filtration techniques to improve and refine water cleaning technology.

These one-celled organisms eat the contaminants present in water — whether it is being treated prior to industrial use or even for drinking — in a process called bioremediation.

The water is then filtered through porous membranes, which function like a sieve. However, the holes in these sieves are microscopic, and some are so small they can only be seen at the nanoscale. Pore size in these filters can range from ten microns — ten thousandths of a millimetre — to one nanometre — a millionth of a millimetre.

UCLA biochemists and colleagues have answered an important question about the structure of microcompartments — the mysterious molecular machines that seem to be present in a wide variety of pathogens and other bacteria.

In the Feb. 22 issue of the journal Science, the biochemists report how the microcompartment structure closes in three dimensions, forming a shell around the enzymes encased inside.

If scientists could prevent or disrupt the formation of these microcompartments, they could probably render the bacteria harmless, said research co-author Todd O. Yeates, UCLA professor of chemistry and biochemistry and a member of the UCLA–Department of Energy Institute of Genomics and Proteomics. They do not yet know how to do this, but the current research may provide a framework for targeting microcompartments.

- New understanding of how big molecules bind will lead to better drugs, synthetic organic materials

February 21, 2008 07:00 PM

Biological and medical research is on the threshold of a new era based on better understanding of how large organic molecules bind together and recognise each other. There is great potential for exploiting the molecular docking processes that are commonplace in all organisms to develop new drugs that act more specifically without adverse side effects, and construct novel materials by mimicking nature.

A recent workshop on Biosupramolecular Chemistry organised by the European Science Foundation (ESF) strengthened Europe’s platform for progress towards these goals by bringing together scientists in the relevant fields and identifying key research targets. The workshop also identified some applications close to fruition, including the engineering of bacteria to produce silks as strong for their thickness as spider webs. It has been a longstanding challenge to emulate the mechanical properties of spider silk, which combines stiffness and tensile strength with the ability to become elastic under high strains to protect against destruction. A recent project led by Thomas Scheibel at the Technical University of Munich is close to a solution that could have a host of practical applications ranging from biodegradable fishing line to body armour.

The first flight by a commercial airline to be powered partly by biofuel has taken place. A Virgin Atlantic jumbo jet has flown between London's Heathrow and Amsterdam using fuel derived from a mixture of Brazilian babassu nuts and coconuts.

Environmentalists have branded the flight a publicity stunt and claim biofuel cultivation is not sustainable.

Earlier this month, Airbus tested another alternative fuel - a synthetic mix of gas-to-liquid.Virgin boss Sir Richard Branson said the flight marked a "vital breakthrough" for the entire airline industry.

"This pioneering flight will enable those of us who are serious about reducing our carbon emissions to go on developing the fuels of the future," he said.

SHENZHEN, China (Reuters) - Chinese scientists are trying to find out which errant genes are responsible for diabetes and certain forms of cancer that have long plagued Chinese populations, a geneticist said.

Rising affluence, richer diets and a sedentary lifestyle have led to an alarming rise in cases of diabetes in China in recent decades, while cancers of the esophagus, lungs, breast, stomach and colon have plagued Chinese people for a much longer time.

The partly state-funded Beijing Genomics Institute (BGI), which completed the mapping out of the first Chinese human genome in 2007, is trying to figure out which genes may be responsible for these chronic and even terminal illnesses.